The continental crust of southeast Asia underwent from thickening, thinning to almost rifting during the Mesozoic era as the active continental margin transformed into a passive one. Such crustal thinning history is well-preserved in the Kinmen Island, as the lower crustal granitoids retrograded and rapidly exhumed to surface that were crosscutted by mafic dike swarm. Kinmen Island is situated on the SE coast of Asia, featured by the widespread Cretaceous magmatism as the Paleo-Pacific plate subducted and rollbacked underneath the South China block. Although these complex magmatism are well reported and studied, their associated structural evolution and plate kinematics have not been clearly deciphered. Detailed field mapping, structural measurement, and petrographic analysis of the Kinmen Island were conducted. Up to five deformation events accompanied with five relevant magmatic episodes as well as their corresponding kinematic setting are reconstructed. The ∼129 Ma Chenggong Tonalite (G₁) preserved all deformation events identified in this study, which marks the lower bound timing of all reported events. D₁ formed a gneiss dome with the Taiwushan Granite (∼139 Ma) at the core bounded by moderately dipping gneissic foliation (S₁) as crust extended. D₂ formed subhorizontal S-tectonite (S₂) with further exhumation of D₁ gneiss dome due to middle-to-lower crustal flow associated with further crustal thinning. D₃ formed a sinistral ENE-WSW striking steeply S dipping shear belts with well-developed S/C/C’ fabrics. The moderately E-plunging lineation on C surface indicates its transtensional nature. Widespread garnet-bearing leucogranite (G₂) associated with decompressional melting showed long lasting intrusion prior to D₂ until post D₃. D₄ was the intrusion of biotite-bearing Tienpu Granite (∼100 Ma; G₃) that truncated G₁, G₂, and all fabrics, which was followed by the intrusion of E-W striking, steeply dipping biotite-bearing pegmatite (G₄) as the crust further extended. The youngest deformation event (D₅) was NE-SW striking subvertical mafic dike swarm (G₅; 90–76 Ma) due to mantle upwelling through significantly thinned crust. By integrating the structural evolution and the previously reported strain pattern, we delineate the slab rollback direction of the Paleo-pacific plate, which changed from northeastward (129∼114 Ma) to southeastward (107∼76 Ma). This plate kinematic movement switched during 114–107 Ma.

在中生代，随着活跃的大陆边缘转变为被动的边缘，东南亚的大陆壳经历了从增厚，变薄到几乎裂谷的过程。这样的地壳变薄历史在金门岛得到了很好的保存，因为较低的地壳花岗石会逆行并迅速发掘到被黑手党堤防横切的地表。金门岛位于亚洲东南部海岸，其特征是白垩纪广泛的岩浆作用，古太平洋板块在华南地块之下俯冲并回滚。尽管对这些复杂的岩浆作用进行了很好的报道和研究，但尚未清楚地解释它们的相关构造演化和板块运动学。对金门岛进行了详细的野外测绘，结构测量和岩石学分析。最多重建五个变形事件，并伴有五个相关的岩浆事件及其相应的运动学背景。〜129马呈贡角质石（G₁）保留了本研究中确定的所有变形事件，这标志着所有报告事件的下限时序。D ₁与太武山花岗岩（约139 Ma）形成了一个片麻岩穹顶，其核心是随着地壳的延伸适度浸入片麻岩片层（S ₁）。D ₂形成水平下的S膨润土（S ₂），D ₁片麻岩穹顶进一步掘出，这是由于与壳层进一步变薄相关的中下地壳流动。D ₃用发达的S / C / C'织物形成了一条陡峭的S浸渍剪切带，形成了一个ENE-WSW左旋。C表面适度的E插入线表示其拉伸性质。石榴石广泛分布的亮花岗岩（G ₂）与减压融化相关的数据显示，在D ₂之前，直到D ₃之后，都会出现长时间的侵入。D ₄是侵入黑云母的天普花岗岩（〜100 Ma; G ₃），其截断了G ₁，G ₂和所有织物，随后是EW撞击，陡峭地浸渍了黑云母伟晶岩（G ₄），随着地壳的进一步延伸。最年轻的变形事件（D ₅）是NE-SW撞击亚垂直铁镁质堤防群（G ₅; 90-76 Ma）是由于地壳明显变薄引起的地幔上升。通过整合结构演化和先前报道的应变模式，我们描绘了古太平洋板块的平板回滚方向，从东北（129〜114 Ma）向东南（107〜76 Ma）变化。板块运动在114–107 Ma期间切换。